Purchasing the season pass before January 15th would have rewarded you with the sparrow. Any date after will unfortunately not give you the sparrow. If purchased before the above date then check your special orders as it will be there if you met the requirements. If not sadly you will not be able to obtain the sparrow. There is no information on future sparrows or interest of releasing the tumbler in the future. Check back with bungie for their weekly updates and the upcoming expansions as a sparrow similar if not better will be present for you and all of us to obtain. Sorry about that.